How Bird Poop Nearly Destroyed California's Power Grid

The proud eagle, noble symbol of freedom. But when you gotta go, you gotta go. Image courtesy of IStock.

In 1923, Southern California Edison had a problem. After having tapped into hydroelectric dams in the Sierra Nevada to serve their power-hungry Los Angeles customers with 220,000 volts, the company began receiving reports of short circuits and resulting power interruptions.

Finding the source of the issue would be no easy feat: The cables connecting the dams to the city stretched for 241 miles—at the time, the world’s longest—and the problem could be anywhere along the way.

Edison employees huddled for a solution, speculating on everything from lightning storms to spider webs holding moisture. Months passed with no plausible reason for the outages. A planned upgrade was in danger of being canceled. Big Creek, the site of the dams, had done everything it could to rearrange nature to suit its needs: forests were altered, clouds seeded. Everything seemed to be in order.

Eventually, an explanation was within sight: one worker noticed an eagle surveying the land from the top of a transmission tower. The majestic creature took off, soaring into the sky—and leaving a less-than-majestic trail of poop in its wake.

This bird had plenty of friends. It turned out that flocks of birds producing "voluminous streams of bird excrement" were to blame for the power outages.

Etienne Benson, P.h.D., a University of Pennsylvania professor, recently examined this fecal mystery in a paper [PDF] for the Environmental Humanities journal. Drawing upon the work of engineer Harold Michener and the power company's archives, Benson discovered accounts of the poo conducting electricity from the wires, overloading capacity, and creating flashovers, which diverted power to the steel towers and into the ground. The feces didn’t even need to touch the wires to pass along electricity. And because the energy essentially destroyed the droppings, the birds left no evidence of their dastardly doo doo. It was the perfect crime.

Once Edison determined the problem was excrement, they had to find a way to address it. Fortunately, among Edison’s employees tasked with a solution was the engineer Michener, who also happened to be an amateur ornithologist. The company first installed relays that took some of the load off areas that were used for avian toilet trips, then installed bird guards to prevent vulnerable areas.

The birds, however, would not be so easily dissuaded. They just moved to the next closest perch; because of wind, their poop had a reach farther than Edison had anticipated. Unable to deter the birds from landing, the company next installed excrement pans to catch the feces before it landed on the power line. When that didn’t prove entirely successful, three-inch iron “teeth” were placed on crossbeams, making landing a painful proposition for the birds.

The combination of poop-catch pans and unwelcoming spikes finally brought down the number of flashovers—and killed all the other competing theories for the cause of the problems. As Benson writes: “That is, it was not some mysterious and spectacular new electrical phenomena, as yet undiscovered by scientists, that was to blame for the flashovers, but rather something far more mundane: bird [poop].”

[h/t Science Daily]

Crafty Crows Can Build Tools From Memory

Scientists have discovered yet another reason to never get on a crow's bad side. According to new research reported by Gizmodo, members of at least one crow species can build tools from memory, rather than just copying the behavior of other crows—adding to the long list of impressive skills that set these corvids apart.

For the new study, published in the journal Scientific Reports, an international team of scientists looked at New Caledonian crows, a species known for its tool usage. New Caledonian crows use sticks to pick grubs out of logs, sometimes stashing these twigs away for later. Tools are so important to their lifestyle that their beaks even evolved to hold them. But how exactly the crows know to use tools—that is, whether the behavior is just an imitation or knowledge passed down through generations—has remained unclear until now.

The researchers set up the experiment by teaching eight crows to drop pieces of paper into a box in exchange for food. The birds eventually learned that they would only be rewarded if they dispensed either large sheets of paper measuring 40-millimeters-by-60 millimeters or smaller sheets that were 15-millimeters-by-25 millimeters. After the crows had adapted and started using sheets of either size, all the paper was taken away from them and replaced with one sheet that was too big for the box.

The crows knew exactly what to do: They ripped up the sheet until it matched one of the two sizes they had used to earn their food before and inserted it into the dispenser. They were able to do this with out looking at the sheets they had used previously, which suggests they had access to a visual memory of the tools. This supports the "mental template matching" theory—a belief among some crow experts that New Caledonian crows can form a mental image of a tool just by watching another crow use it and later recreate the tool on their own, thus passing along the template to other birds including their own offspring.

This is the first time mental template matching has been observed in birds, but anyone familiar with crow intelligence shouldn't be surprised: They've also been known to read traffic lights, recognize faces, nurse grudges, and hold funerals for their dead.

[h/t Gizmodo]

These Sparrows Have Been Singing the Same Songs for 1500 Years

Swamp sparrows are creatures of habit—so much so that they’ve been chirping out the same few tunes for more than 1500 years, Science magazine reports.

These findings, published in the journal Nature Communications, resulted from an analysis of the songs of 615 adult male swamp sparrows found in six different areas of the northeastern U.S. Researchers learned that young swamp sparrows pick up these songs from the adults around them and are able to mimic the notes with astounding accuracy.

Here’s what one of their songs sounds like:

“We were able to show that swamp sparrows very rarely make mistakes when they learn their songs, and they don't just learn songs at random; they pick up commoner songs rather than rarer songs,” Robert Lachlan, a biologist at London’s Queen Mary University and the study’s lead author, tells National Geographic.

Put differently, the birds don’t mimic every song their elders crank out. Instead, they memorize the ones they hear most often, and scientists say this form of “conformist bias” was previously thought to be a uniquely human behavior.

Using acoustic analysis software, researchers broke down each individual note of the sparrows’ songs—160 different syllables in total—and discovered that only 2 percent of sparrows deviated from the norm. They then used a statistical method to determine how the songs would have evolved over time. With recordings from 2009 and the 1970s, they were able to estimate that the oldest swamp sparrow songs date back 1537 years on average.

The swamp sparrow’s dedication to accuracy sets the species apart from other songbirds, according to researchers. “Among songbirds, it is clear that some species of birds learn precisely, such as swamp sparrows, while others rarely learn all parts of a demonstrator’s song precisely,” they write.

According to the Audubon Guide to North American Birds, swamp sparrows are similar to other sparrows, like the Lincoln’s sparrow, song sparrow, and chipping sparrow. They’re frequently found in marshes throughout the Northeast and Midwest, as well as much of Canada. They’re known for their piercing call notes and may respond to birders who make loud squeaking sounds in their habitat.

[h/t Science magazine]


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